''Rossiteria nucleus'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

sea snail Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the ...

, a marine

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Trochidae The Trochidae, common name top-snails or top-shells, are a family of various sized sea snails, marine gastropod molluscs in the subclass Vetigastropoda. This family is commonly known as the top-snails because in many species the shell resembles ...

, the top snails.Bouchet, P. (2014). Rossiteria nucleus (Philippi, 1849). Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=547287 on 2014-07-21

Description

The height of the shell attains 9 mm, its diameter also 9 mm. The solid shell is narrowly umbilicate and has a globose-conoida shape. It is whitish, maculated with chestnut, sometimes banded, often punctate and articulated with white dots. The conic

spire A spire is a tall, slender, pointed structure on top of a roof of a building or tower, especially at the summit of church steeples. A spire may have a square, circular, or polygonal plan, with a roughly conical or pyramidal shape. Spires are ...

is acute and short. The sutures are impressed. The 5 to 6

whorl A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). Whorls in nature File:Photograph and axial plane floral ...

s are convex, decussated by spiral lirae and close, strong longitudinal striae. The lirae usually contain intermediate lirulae. The whorls are often a little flattened below the suture, with a slight angle at the shoulder. The

body whorl The body whorl is part of the morphology of the shell in those gastropod mollusks that possess a coiled shell. The term is also sometimes used in a similar way to describe the shell of a cephalopod mollusk. In gastropods In gastropods, the b ...

is globose and convex. The

aperture In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. An opt ...

is slightly oblique. The outer and basal lips are closely lirate within. The short columella is concave, its edge plicate-denticulate, terminating below in a tooth. The white umbilicus is funnel-shaped. It is margined by a slight convexity terminating below the columellar tooth. This is a peculiar little species, of globose form, with truncated columella, lirate interior, and finely decussated surface. The color pattern is very variable.H. Pilsbry (1889), Manual of Conchology XI, Academy of Natural Sciences, Philadelphia
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Distribution

This marine species occurs off

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...

, the

Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

, the

Fiji Islands Fiji ( , ,; fj, Viti, ; Fiji Hindi: फ़िजी, ''Fijī''), officially the Republic of Fiji, is an island country in Melanesia, part of Oceania in the South Pacific Ocean. It lies about north-northeast of New Zealand. Fiji consists ...

and the

Great Barrier Reef The Great Barrier Reef is the world's largest coral reef system composed of over 2,900 individual reefs and 900 islands stretching for over over an area of approximately . The reef is located in the Coral Sea, off the coast of Queensland, ...

, Australia and

New Caledonia ) , anthem = "" , image_map = New Caledonia on the globe (small islands magnified) (Polynesia centered).svg , map_alt = Location of New Caledonia , map_caption = Location of New Caledonia , mapsize = 290px , subdivision_type = Sovereign st ...

References

* Dautzenberg, Ph. (1929). ''Contribution à l'étude de la faune de Madagascar: Mollusca marina testacea''. Faune des colonies françaises, III(fasc. 4). Société d'Editions géographiques, maritimes et coloniales: Paris. 321–636, plates IV–VII pp. * Poppe G.T., Tagaro S.P. & Dekker H. (2006) ''The Seguenziidae, Chilodontidae, Trochidae, Calliostomatidae and Solariellidae of the Philippine Islands''. Visaya Supplement 2: 1–228. page(s): 110

External links

* {{DEFAULTSORT:Rossiteria Nucleus

nucleus Nucleus ( : nuclei) is a Latin word for the seed inside a fruit. It most often refers to: *Atomic nucleus, the very dense central region of an atom *Cell nucleus, a central organelle of a eukaryotic cell, containing most of the cell's DNA Nucle ...

Gastropods described in 1849